Snapshot A 4-month old female was referred by a local clinic for evaluation of asymmetric thigh creases during routine checkup. Physical exam revealed that the left lower limb was shorter than the right and lay externally rotated. Hip abduction was limited to 30 degrees. Ortolani's test was positive. Radiographs revealed a superiorly displaced left proximal femoral metaphysis and a shallow, hypoplastic left acetabulum. The infant was treated in a Pavlik abduction harness for congenital hip dislocation. Introduction Most common orthopaedic disorder in newborns Developmental dysplasia/dislocation of the hip (DDH) A spectrum of conditions characterized by varying displacement of the proximal femur from the acetabulum including dislocation: complete loss of contact between acetabulum and femoral head subluxation: femoral head partially outside acetabulum subluxable: subluxed with exam maneuvers, mild instability or laxity dysplasia: abnormality of the hip joint shape, usually shallowness Results from poor development of the acetabulum and hip due to excessive uterine packing which causes excessive stretching of the posterior hip capsule and adductor muscle contractures Deformity will progress if it is not corrected Etiology Risk factors - the 4 F's females firstborns fanny first (breech presentations) family history of DDH Presentation Idenitfy through screening physical exam asymmetric skin folds limited hip abduction on affected side Barlow's test test of dislocation applied to dislocatable (but not already dislocated) hips flex and adduct hips, apply light pressure on knees, directing force posteriorly test is positive if hip dislocates posteriorly Ortolani's test test of reduction (performed immediately after Barlow maneuver) applied to an already dislocated hip lay infant supine, flex hips and knees to 90 degrees, apply anterior pressure on the greater trochanters using index fingers, gently abduct the hips using thumbs produces soft "clunk" with anterior relation of the femoral head into the acetabulum Galeazzi's test check if knees at unequal heights when the hips and knees are flexed dislocated side will be lower Trendelenburg sign in walking patients a dip of the pelvis in the opposite side when the patient stands on the affected leg Trendelenburg sign also seen in superior gluteal nerve injury Imaging Clinical exam Ultrasound Radiographs are unreliable until the patient is at least four months old because of radiolucency of femoral head Treatment < 6 months old Pavlik harness (abduction bracing) keep hips flexed and abducted do not abduct > 60 degrees (increased risk of AVN) Can observe until up to 4 weeks of age to allow for spontaneous resolution without risk of jeopardizing future interventions 6-18 months old closed reduction and hip spica cast >18 months old open reduction followed by hip spica cast Complications Joint contractures AVN of the femoral head Prognosis Better if treatment begins earlier